Background art tracer systems other than the applicant's system have shorter active release periods and have erosion- or dissolution-based release of the tracer chemicals. This requires a fundamentally different approach during interpretation than for the present invention since the release of such background art systems is more directly linked to the production rates. Longevity in wells may in such cases generally not be predicted since the tracer will be used up rather according to cumulative production volume than being released at a constant rate with time.
In an embodiment of the invention it is suggested to arrange array of mechanical chambers that is placed along the production zone and will give a tracer shot per location at given synchronized points in time. The tracer shots that are created will travel to the surface with the produced fluids. Flow profiles may be estimated from the measurements of concentration of the different tracer materials conducted at the surface or elsewhere downstream.